The Mass Spectrometry and Proteomics (MSP) Shared Resource provides Huntsman Cancer Institute (HCI) members and the entire University of Utah research community a broad range of mass spectrometry services, including state-of-the-art instrumentation, consultation, and expertise, particulariy for proteomics-based research. The hybrid Fourier-Transform mass spectrometer (model LTQ-FT, ThermoElectron) is the main proteomics instrument. It provides protein identification (ID) at levels as low as 50 attomole, high-mass accuracy (<2ppm), and peptide sequencing by electron-capture dissociation (ECD), infrared multiphoton dissociation (IRMPD), and collision-induced dissociation (CID). Proteomics services include protein ID; characterization of post-translational modifications (e.g., phosphorylafion); and analysis of intact proteins. The Resource also provides mass spectrometry services for a wide range of other research applications such as structural analysis of natural products, drugs and drug-polymer conjugates, nucleic acids, DNA amplification products (e.g., PCR), large biomolecules and polymers, pepfides, and small synthetic molecules. Chad Nelson, PhD, has directed the MSP Shared Resource since 2003, with the assistance of two staff members. The instrumentation and staff of the MSP Shared Resource are centrally located. The MSP Shared Resource serves all HCI laboratory-based scientific Programs (Nuclear Control of Cell Growth and Differentiafion; Cell Response and Regulafion; Imaging, Diagnosfics, and Therapeufics; and Gastrointesfinal Cancers), characterizing molecules, particulariy proteins and post-translational modifications, that play roles in cancer mechanisms. In addition, characterization of small compounds by the MSP Shared Resource, including natural products and drug-delivery polymers, contributes significantly to the developmental therapeufics activifies of HCI. The MSP Shared Resource is an institutionally managed facility with supervision from both University and HCI leadership. There is a Faculty Advisory Committee and the Resource is reviewed for user satisfaction by annual surveys. The facility is operated on a fee-for-service basis (chargeback). In 2008, overall use of the MSP Shared Resource by Cancer Center members with peer-reviewed funding and Cancer Center Shared Resources was 31 percent. Funds are requested from the CCSG to cover 14 percent ($44,857) of the proposed Resource budget. The MSP Shared Resource has ample capacity for additional use by Cancer Center members.